Climate variability in the North Atlantic has been linked in part to the North Atlantic Oscillation (NAO). The NAO influences marine ecosystems in the northwestern Atlantic and the transport variability of the cold Labrador Current (LC). Understanding historic patterns and predicting future changes in LC transport require long-term and high-resolution climate records that are not available from instrumental data sets. This thesis presents the first century-scale sea surface temperature (SST)reconstructions from the Northwestern Atlantic using Mg/Ca ratios in the long-lived crustose coralline algae Clathromorphum compactum. which is characterized by a high Mg-calcite skeleton exhibiting annual growth increments. Results indicate strong correlations between interannual variations in Mg/Ca ratios and instrumental SST. The 131-year algal Mg/Ca record reveals NAO-type periodicities and evidence of past cold events and warming periods associated with basin-wide ecosystem shifts. Negative correlations between LC volume transport and algal Mg/Ca reflect the cooling influence of the LC on eastern Canadian shelf ecosystems.

In urban areas, emissions of nitrogen oxide radicals (NOx ≡ NO + NO2) to the atmosphere from anthropogenic activities such as fossil fuel combustion contribute to poor air quality through the production of ozone and particulate matter. Soils are also a significant global source of NOx, but at downind forest environments the deposition of transported reactive nitrogen can be much more important than local emissions. Data from a government monitoring network in the Toronto area from 2000-2007 was used to explore the impact of long-term trends in NO2 and other ozone precursors on local ozone levels. Non-linear chemistry and the influence of meteorology explained why reductions in precursor levels during this period did not lead to significant improvements in ozone. Data from this network was also used to investigate the ability of a satellite-borne spectrometer to represent spatial patterns of ground-level NO2 in the same region. Selection biases, resulting from the need to discard satellite data on cloudy days, were shown to affect locations differently and were most severe at a receptor site. The sum of all reactive nitrogen oxides including NOx is known as NOy. A custom-built instrument for high precision and time resolution measurements of reactive nitrogen oxides was tested under various lab and field conditions, and used in field work where direct biosphere-atmosphere exchange of NOy was measured by eddy covariance above two comparable North American mixed forests (Haliburton Forest Wildlife Reserve and the University of Michigan Biological Station). While these forests were found to be small net sources of NOx, they were subject to elevated rates of NOy deposition overall, driven by the transport of polluted air from upwind source regions. Wet deposition measurements were used to show that dry deposition contributed a significant fraction of total deposition during the observation periods.

Mechanistic aspects of carbonaceous aerosol toxicity were examined with respect to the ability of particles to catalyse reactive oxygen species-generating redox cycling reactions. To investigate the role of secondary organic material, we examined two systems. In the first, two-stroke engine exhaust particles were found to increase their ability to catalyse redox cycling in the presence of a reducing agent, dithiothreitol (DTT), when the exhaust was exposed to ozone. This occurred through deposition of redox-active secondary organic aerosol (SOA) onto the particle that was ten times more redox active per microgram than the primary engine particle. In the second system, naphthalene SOA formed highly redox active particles. Activity was strongly correlated to the amount of the 1,4- and 1,2-naphthoquinone measured in the particle phase. However, these species and the newly quantified naphthalene oxidation product 5-hydroxy-1,4-naphthoquinone accounted for only 30% of the observed DTT decay from the particles. Gas-particle partitioning coefficients suggest 1,4- and 1,2-naphthoquinone are not strong contributors to ambient particle redox activity at 25°C. However, a large number of redox active species are unidentified. Some of these may be highly oxidised products of sufficiently low vapour pressure to be atmospherically relevant. DTT activity of diesel particles was found to be high per unit mass. The activity was found to be associated with the insoluble fraction as filtration of the particles nearly eliminated DTT decay. Neither methanol nor dichloromethane extracts of diesel particles exhibited redox activity, indicating that the redox active species are associated with the black carbon portion of the particles. Examination of particle concentration techniques found that use of water condensation to grow and concentrate particles introduced a large organic artefact to the particles. Experiments with concentrated inorganic particles suggest that the source of this artefact is from irreversible uptake of water-soluble volatile organic compounds. Overall, carbonaceous redox active species can be thought of as a continuum from small, water-soluble species to redox active functionalities on elemental carbon backbones. In addition to clearly defined, quantifiable species, future research may need to consider examining broader chemical classes or redox-active chemical functionalities to overcome the inherent complexity of these constituents.

The aqueous phase photo-oxidation of water soluble organic compounds (WSOC) extracted from α-pinene ozonolysis secondary organic aerosol (SOA) was investigated using high resolution time-of-flight chemical ionization mass spectrometry (CI-ToFMS). The results have shown that WSOC get more functionalized and fragmented as the reaction proceeds. The capabilities of three reagent ions, were assessed; specifically, (H2O)nH+ ionizes organic compounds with carbon oxidation state (OSC) ≤ 1.3, whereas CH3C(O)O- and I(H2O)n- ionize highly oxygenated organics with OSC up to 4, with I(H2O)n- showing more selectivity. The aqueous phase OH oxidation of cis-pinonic acid and tricarballylic acid (a surrogate for 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), recognized as a tracer of α-pinene SOA) were also studied. The respective rate constants at 301 K were measured to be 3.4(±0.5)×10^9 M^-1s^-1 at pH=2 and 3.1(±0.3)×10^8 M^-1s^-1 at pH=4.6. This work also illustrates possible aqueous phase mechanism for MBTCA formation from cis-pinonic oxidation.

In urban areas, emissions of nitrogen oxide radicals (NOx ≡ NO + NO2) to the atmosphere from anthropogenic activities such as fossil fuel combustion contribute to poor air quality through the production of ozone and particulate matter. Soils are also a significant global source of NOx, but at downind forest environments the deposition of transported reactive nitrogen can be much more important than local emissions. Data from a government monitoring network in the Toronto area from 2000-2007 was used to explore the impact of long-term trends in NO2 and other ozone precursors on local ozone levels. Non-linear chemistry and the influence of meteorology explained why reductions in precursor levels during this period did not lead to significant improvements in ozone. Data from this network was also used to investigate the ability of a satellite-borne spectrometer to represent spatial patterns of ground-level NO2 in the same region. Selection biases, resulting from the need to discard satellite data on cloudy days, were shown to affect locations differently and were most severe at a receptor site. The sum of all reactive nitrogen oxides including NOx is known as NOy. A custom-built instrument for high precision and time resolution measurements of reactive nitrogen oxides was tested under various lab and field conditions, and used in field work where direct biosphere-atmosphere exchange of NOy was measured by eddy covariance above two comparable North American mixed forests (Haliburton Forest Wildlife Reserve and the University of Michigan Biological Station). While these forests were found to be small net sources of NOx, they were subject to elevated rates of NOy deposition overall, driven by the transport of polluted air from upwind source regions. Wet deposition measurements were used to show that dry deposition contributed a significant fraction of total deposition during the observation periods.

Mechanistic aspects of carbonaceous aerosol toxicity were examined with respect to the ability of particles to catalyse reactive oxygen species-generating redox cycling reactions. To investigate the role of secondary organic material, we examined two systems. In the first, two-stroke engine exhaust particles were found to increase their ability to catalyse redox cycling in the presence of a reducing agent, dithiothreitol (DTT), when the exhaust was exposed to ozone. This occurred through deposition of redox-active secondary organic aerosol (SOA) onto the particle that was ten times more redox active per microgram than the primary engine particle. In the second system, naphthalene SOA formed highly redox active particles. Activity was strongly correlated to the amount of the 1,4- and 1,2-naphthoquinone measured in the particle phase. However, these species and the newly quantified naphthalene oxidation product 5-hydroxy-1,4-naphthoquinone accounted for only 30% of the observed DTT decay from the particles. Gas-particle partitioning coefficients suggest 1,4- and 1,2-naphthoquinone are not strong contributors to ambient particle redox activity at 25°C. However, a large number of redox active species are unidentified. Some of these may be highly oxidised products of sufficiently low vapour pressure to be atmospherically relevant. DTT activity of diesel particles was found to be high per unit mass. The activity was found to be associated with the insoluble fraction as filtration of the particles nearly eliminated DTT decay. Neither methanol nor dichloromethane extracts of diesel particles exhibited redox activity, indicating that the redox active species are associated with the black carbon portion of the particles. Examination of particle concentration techniques found that use of water condensation to grow and concentrate particles introduced a large organic artefact to the particles. Experiments with concentrated inorganic particles suggest that the source of this artefact is from irreversible uptake of water-soluble volatile organic compounds. Overall, carbonaceous redox active species can be thought of as a continuum from small, water-soluble species to redox active functionalities on elemental carbon backbones. In addition to clearly defined, quantifiable species, future research may need to consider examining broader chemical classes or redox-active chemical functionalities to overcome the inherent complexity of these constituents.

The aqueous phase photo-oxidation of water soluble organic compounds (WSOC) extracted from α-pinene ozonolysis secondary organic aerosol (SOA) was investigated using high resolution time-of-flight chemical ionization mass spectrometry (CI-ToFMS). The results have shown that WSOC get more functionalized and fragmented as the reaction proceeds. The capabilities of three reagent ions, were assessed; specifically, (H2O)nH+ ionizes organic compounds with carbon oxidation state (OSC) ≤ 1.3, whereas CH3C(O)O- and I(H2O)n- ionize highly oxygenated organics with OSC up to 4, with I(H2O)n- showing more selectivity. The aqueous phase OH oxidation of cis-pinonic acid and tricarballylic acid (a surrogate for 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), recognized as a tracer of α-pinene SOA) were also studied. The respective rate constants at 301 K were measured to be 3.4(±0.5)×10^9 M^-1s^-1 at pH=2 and 3.1(±0.3)×10^8 M^-1s^-1 at pH=4.6. This work also illustrates possible aqueous phase mechanism for MBTCA formation from cis-pinonic oxidation.

The investigation of the atmospheric fate and transport of semi-volatile organic compounds (SOCs) often requires the sampling of large volumes of air (>100 m3) in a relatively short period of time. Conventionally high-volume pumps are not suitable for remote areas without access to reliable network power. We have developed a flow through sampler for such situations. It consists of a horizontally-oriented flow-tube, that can collect gaseous and particle-bound SOCs from large volumes of air by turning into the wind and having the wind blow through a porous sampling medium such as polyurethane foam. Through both indoor and outdoor experiments, we quantified its air sampling rate (through battery operated anemometers inside and outside of the flow tube), its sampling efficiency (by theoretical plate number analysis of the break-though curves for PCBs, PAHs, OCPs and PBDEs), and its accuracy (by comparison of concentrations, time trends, temperature dependences and isomer ratios with those obtained by conventional high-volume sampling) under conditions of constant and variable meteorological conditions (wind speed, temperature). The flow-through sampler was deployed to monitor SOC concentrations at a remote Chinese research station located close to Nam Co Lake, Tibet. During the campaign, fifteen 1 month-long samples were taken, corresponding to sample volumes between 5,000 and 20,000 m3. Despite those large sample volumes, only HCB and HCHs experienced break-through, but application of frontal chromatograph theory allows the estimation of breakthrough-corrected air concentrations even for those relatively volatile SOCs. The pesticide levels at Nam Co are generally very low. Most pesticides had higher levels during summer, resulting in a strong temperature dependence. This is correlated with air mass origin across the Himalayas in the Gangetic plains of India and Bangladesh. The flow through sampler constitutes a feasible method for reliably and quantitatively collecting SOCs from large air volumes.

Master of Science / Apparel, Textiles, and Interior Design / Sherry J. Haar / This study compared the colorfastness of potassium aluminum sulfate (PAS) mordanted and nonmordanted 30/2 wool yarn, dyed with black walnut (Juglans Nigra), Osage orange (Maclura pomifera), and eastern redcedar (Juniperus virginiana) sawdust. Information from this study is intended to inform natural dye artisans and to increase the profitability of sawdust for farmers, ranchers, and mill owners who would otherwise find little use for this byproduct of timber manufacturing. Pre-testing ensured dyeings of visually comparable color depth and dye concentrations were pre-tested to find a standard depth of shade between the same dye on PAS mordanted and nonmordanted wool yarns. Tests for colorfastness to light, laundering and staining were performed in accordance to AATCC test methods. Resulting colors for exposed and unexposed specimens were rated using CIE L* a* b* values and AATCC gray scale for color change. GLM Anovas and two-sample t-tests were used to statistically analyze CIE L* a* b* values. As expected, findings indicated that dye absorption was improved with the use of a PAS mordant, especially for black walnut and eastern redcedar. For yarns premordanted with PAS the dyewoods became yellower. A PAS mordant slightly improved colorfastness to light for black walnut and eastern redcedar, but did not influence Osage orange which had an unexpected color change from bright yellow to warm brown after exposure to light. Colorfastness to laundering was slightly improved with PAS for Osage orange, while black walnut and eastern red cedar had slightly less color change without the mordant. This research was supported by the Agricultural Research Experiment Station and Kansas State University.

Master of Science / Department of Journalism and Mass Communications / Joye C. Gordon / Global warming and its implications have astounding consequences for the global community. Although some research has been done on the trends within environmental reporting, few studies have looked at the issue of global warming in particular. Global warming is a troublesome issue for reporters for a number of reasons, and hence, it is important that we delve into how newspapers cover the topic. Latin America, especially the Caribbean region, is expected to suffer extreme consequences due to global warming, yet no studies regarding global warming coverage have been done in these regions. The first purpose of this study was to discover how a Mexico newspaper frames the issue of global warming. Next, this study sought to expand the current knowledge of global warming coverage by the media. Lastly, this study sought to expand on existing literature to discover how journalists outside of the United States communicate, to the public, the issue of global warming. Based on previous studies on global warming a frame analysis was conducted to explore how the Mexico City-based newspaper Reforma covers the issue of global warming. This study identified that ecology/science and consequences are the most frequently occurring themes of coverage, while scientific conflict and North/South conflict are present, but in low frequencies and near the end of stories. This study also identified international relations as the most frequent solution to global warming, while global warming story frequencies peaked during international conferences. These results confirm previous research, which has found that news media outside of the United States tend to emphasize international relations and de-emphasize conflicts and controversies.